Fabrication of Bucco-matrix tablets of Amoxicillin trihydrate on the basis of release and permeation kinetics

Drug release kinetics from matrix dosage form is governed by polymer swelling and erosion, drug dissolution/diffusion and polymeric combination. For the preparation of controlled release dosage form, hydrophilic, swellable polymers in optimum combination are essential. The major objective of the current study is to prepare Amoxicillin trihydrate-loaded bucco-matrix tablets by direct compression technique and to study the effect of ratio of HPMCK100M and HPMCK15M used in the formulation on the basic properties and on drug-release and permeation kinetics. The tablets offered satisfactory physicochemical results. The buccal strength, detachment force and bond strength of the tablets were good enough to hold the tablets in the buccal region. The drug release data generated during in vitro drug release study of bucco-matrix tablets in phosphate buffer pH 6.8 were evaluated by zero-order, first-order, Higuchi, Korsmeyer – Peppas, and Kopcha models. Release exponent (n) of Korsmeyer- Peppas equation of the formulations exhibited diffusion as the principal mechanism of drug release. It was further confirmed by Kopcha model. Evaluation of diffusion and erosion terms in the Kopcha model showed that diffusion dominated swelling or erosion process throughout the study. The permeation kinetics of the drug showed linearity when studied across goat buccal mucosa. Permeation coefficient of drug decreased with increase in % swelling index of the formulations.